During recent years, the large amount of carbon dioxide emission brought about by fossil fuel burning has led to greenhouse effect and other environmental problems, and all countries in the world have to take carbon dioxide emission reduction measures considering the environment and climate changes resulted from the greenhouse effect. At present, the chemical absorption method is mainly used for collecting carbon dioxide in industrial application, and the main research direction of chemical absorption method is seeking a stable, high effective and low energy consumption absorbent. However, monoethanolamine (MEA), hot potash, amino acid salt and other absorbents in the prior art all have the disadvantages of high energy consumption.
Chinese patent application CN101190397B discloses a carbon dioxide absorbent comprising mixed solution of inorganic salt of amino acid and amine, and the absorbent has a high absorption rate and a large absorption capacity. However, since the compound generated after carbon dioxide is absorbed is relatively stable, the technical problem that the desorption ratio of carbon dioxide is low and a high temperature is needed is not solved essentially.
Chinese patent application CN102658019 discloses a composite activated potash solution used for removing carbon dioxide from flue gas. The composite activated potash solution is composed of alkaline amino acid salt and inorganic acid salt, and the alkaline amino acid salt accounts for 0.5 wt % to 10 wt %. In the aforesaid invention, amino acid salt only serves as activating agent.
In SIEMENS' patent CN102245278, the carbon dioxide absorbent comprises mixture of free amino acid and amino acid salt. The excess amino acid plays the role of regulating the pH value of the absorbent. The absorbent in the aforesaid invention does not comprise organic amine component.
Based on the status quo that large amount of carbon dioxide is emitted, a carbon dioxide absorbent with improved performance is urgently needed.